Immunohistochemical detection of ras 21 in oral squamous cell carcinomas.

The expression of the ras p21 in oral squamous cell carcinoma was examined immunohistochemically with the use of a monoclonal antibody NCC-RAS-001 with the avidin-biotin-peroxidase complex method. The expression of ras p21 product was detected in 65.7% (44 of 67 cases) of cancer patients. On the basis of the degree of histologic differentiation of the cancer cells, the incidence of ras p21 was found to be as follows: 63.4% (26 of 41 cases) were well differentiated; 86.7% (13 of 15 cases) were moderately differentiated; and 45.5% (5 of 11 cases) were poorly differentiated. The highest incidence was found in patients in their sixties--80.0% (16 of 20 cases). The incidence decreased to 40% in patients over 80 years of age. The incidence of ras p21 on the basis of location was as follows: 81.8% (9 of 11 cases) involved the buccal region, 70.6% (12 of 17 cases) were in the gingiva, and 55.0% (11 of 20 cases) were in the tongue.